/*
 * Copyright 2017 JBoss Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.apicurio.hub.editing.metrics;

import java.io.IOException;
import java.io.Writer;

import javax.inject.Inject;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import io.apicurio.hub.core.editing.IEditingMetrics;
import io.prometheus.client.exporter.common.TextFormat;

/**
 * Used to show metrics information.
 * 
 * @author eric.wittmann@gmail.com
 */
public class MetricsServlet extends HttpServlet {

    private static final long serialVersionUID = -2731424958936233258L;

    @Inject
    private IEditingMetrics metrics;

    /**
     * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
     *      javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setStatus(HttpServletResponse.SC_OK);
        resp.setContentType(TextFormat.CONTENT_TYPE_004);
        
        Writer writer = resp.getWriter();
        try {
            writer.write(metrics.getCurrentMetricsInfo());
            writer.flush();
        } finally {
            writer.close();
        }
    }

}
